Field
One or more embodiments relate to a method of preparing a composite cathode active material, a composite cathode active material, and a cathode and a lithium battery containing the composite cathode active material.
Description of the Related Art
In general, a cathode active material for a lithium battery is a transition metal compound or a lithium transition metal oxide such as LiNiO2, LiCoO2, LiMn2O4, LiFePO4, LiNixCo1-xO2 (0≦x≦1), or LiNi1-x-yCoxMnyO2 (0≦x≦0.5 and 0≦y≦0.5). The cathode active material has a limited electrical capacity.
Thus, a novel cathode active material having various structures is suggested. In particular, composite oxides have been suggested according to demand for high capacity batteries.
For example, one of the composite oxides is a xLi2MO3-(1-x)LiMeO2 (where, 0<x<1, M and Me are a transition metal) having a layer structure. In the preparation process of the composite oxide, an initial capacity of the cathode active material may be deteriorated since a previous oxidation of one of the transition metals results in the formation of a cathode active material precursor having a separate additional phase.
Therefore, a cathode active material having an improved discharge capacity and life characteristics by suppressing a formation of an additional phase during a preparation process of a cathode active material precursor is needed.